Convertible top drive unit repair
 

New to the forum, I own a 2004 9.3 ARC Convertible. Have had it since 2006 and has been a great car with few issues, and none that I havent been able to fix myself (with the exception of computer modules of course).
I've had to replace/recondition three hydraulic pistons but not hard to do.
Having found a right hand tonneau piston leaking, and having problems with the "remove items...." warning I've now discovered the spring that powers the panels that hide the top in the boot/trunk when lowered, has become detached. The tubular piece inside the spring has snapped off the bracket, it appears to be a cast aluminium piece.(see attachment)
I have the spring, pivot rod and retaining clip but that is all. I have a machine shop that could reproduce the part but have questions about its mounting onto the (drive unit) bracket. Parts supply houses are out of the complete assembly and someone on Ebay wants $999 for a used one!!!
Any help would be much appreciated.
Thanks
Vince